Self-balancing ionizing circuit for static eliminators

Abstract

A self-balancing ionizing circuit for electrical static eliminators having high voltage (pointed) discharge electrodes employs an insulative duct spaced peripherally thereabout. The duct has at least an open exit end with a non-conductive protective grille at the duct terminus in longitudinally spaced disposition from said electrodes. One side of an ungrounded secondary coil of an A.C. high voltage transformer is directly or resistively connected electrically to the discharge electrodes while the other side of the transformer secondary is electrically coupled to an ungrounded conductive band supported within the insulative duct adjacently spaced from the discharge electrodes to define a floating reference electrode with respect thereto. The electric field for ionization is produced between the discharge electrodes and the reference electrode. Grounding is effected only by way of an external conductive chassis for the system which is shielded from the internal ionization process by the dielectric of the insulative duct. Isolating the reference electrode from ground permits substantial voltages to be developed thereon without creating the ionization imbalance normally produced by adjacent grounded components, such as grounded casings or the like. Balancing of positive and negative ion production is independent of capacitors or other electrical components, and no mechanical adjustment is required to compensate for changes in environmental factors or contamination conditions. With no capacitors which can become leaky, the system provides high reliability with fewer parts, thereby minimizing costs.